1. Field of the Invention
The present invention relates to a mouthpiece of a brass instrument held to one's mouth when a trumpet, trombone, or the like is used.
2. Description of the Related Art
There are various types of brass instruments and, for example, a trumpet is one typical instrument thereof. In a general trumpet, lips vibrate due to a breath blown by a player to generate a sound wave. The sound wave repeatedly travels back and forth in the instrument at the speed of sound and a portion thereof is discharged from the bell.
Incidentally, the mouthpiece is an important part through which air is blown while the mouthpiece being held to one's mouth and includes, as described in Japanese Patent Application Laid-Open Nos. 5-127665, 10-214080, and 2004-61573, each part of a rim, cup, shoulder, throat, back-bore, and shank.
According to Japanese Patent Application Laid-Open No. 5-127665, for example, a mouthpiece is formed from a material of titanium or a titanium alloy, or zirconium or a zirconium alloy as a mouthpiece that is lightweight and will not rust and also provides a tone that is different from conventional one.
According to Japanese Patent Application Laid-Open No. 10-214080, an upper half of a rim is formed to be positioned at a location apart from a player by a predetermined distance with respect to a lower half of the rim so that even a player having occlusion in such a way that lower front teeth are positioned toward the player from upper front teeth when viewed from the player can play in a horizontal form.
According to Japanese Patent Application Laid-Open No. 2004-61573, a satin surface constituted by fine innumerable irregularities is formed on an outer circumferential surface of rim where lips come into contact, the front, and an inner surface of a cup so that a mouthpiece becomes soft on lips, a slip can be prevented to prevent an error caused by a slip during performance, and also fatigue caused by performance can be mitigated.
Various techniques of the mouthpiece of a brass instrument held to one's mouth have been proposed, as described above, but the cup, shoulder, throat, and backbore directly relate to a sense of resistance and a problem of a conventional mouthpiece to be solved is that when lips are fatigued, lips may not vibrate so that no sound is produced.
Particularly, it is generally known that the best place to obtain a moderate sense of resistance is only the throat, places where sound pressure is maximal for all sounds are only the cup and throat, and blowing resistance decreases with an increasing throat diameter and conversely increases with a decreasing throat diameter so that a moderate sense of resistance helps the player, but no technique concerning the throat has been disclosed.
The Bernoulli's theorem of “If the flow rate goes up, pressure drops” is known and applying this theorem to a phenomenon that occurs in a throat part of a mouthpiece yields “If the flow rate goes up by making the throat smaller, sound pressure drops”. From the standpoint of a player, this means that if the throat is made smaller, lips vibrate more easily with increasing blowing resistance, but a loud sound cannot be produced.
The throat has been completely round with a smooth surface and only the throat diameter is changed, for example, in accordance with the brass instrument.
The present invention has been made in view of the above circumstances and an object thereof is to provide a mouthpiece capable of causing lips to vibrate efficiently while having a throat of the size allowing to produce a loud sound so that a brass instrument is made easier to blow, durability is improved, and excellent sound quality can be generated with improved sound production in high tone and low tone areas.